Research And Implementation Of Massive Terrain Data File System

In recent years,with the development of seismic acquisition techniques and the level of computer hardware improving,the high resolution terrain data that are needed in seismic acquisition system have reached the TB level.The traditional processing technology of the terrain data based on memory cannot be used to deal with the massive them.Therefore,for supporting the seismic acquisition operating under the 3D terrain,designing a massive terrain data file system that meet the requirements in the 3D visualization and studying a storage mechanism for large terrain data are needed.The main research contents of this paper are as follows:(1)According to the problem of the multi-resolution storage of massive regular grid(GRID)terrain data,this paper is studying the multi-resolution terrain storage file system(VPBE)based on the quadtree to support the efficient reading and storage of massive GRID terrain data.The terrain data of different resolution are written into the quadtree node files according to the block as well as the position in the files of them.In the process of reading,the position indexes will be read before getting the terrain data.(2)Aiming at the diversity problem of the massive GRID terrain data format,in order to make the VPBE can support storage and query of terrain data in variety of formats,which can lay the foundation for the efficient application of 3D visualization,the corresponding conversion algorithm among them should be studied.The key of the algorithm is to find the appropriate intermediate file format.(3)For the problem of the multi-resolution storage with the massive irregular triangular network(TIN)terrain data,the algorithm is designed to convert this kind of data to the GRID terrain data.Considering the feature of mass and the characteristics of the TIN,this paper adopts the method of traversing the triangles and prefetching the vertex data around to reduce the IO operation as well as interpolating the elevation values of the GRID data.Furthermore,the converted contents will be embedded in the VPBE.Through a large number of experimental data test and actual system deployment operation,it is proved that the massive terrain data file system based on the above research can support the application of the upper terrain visualization and improve the operation effectiveness of the seismic acquisition system.